While several restraint systems have been proposed for use in vehicles, none are entirely suited for use in a school bus for transporting school children.
U.S. Pat. No. 4,681,344 describes a safety hold-down bar system that employs a U-shaped bar to which is connected a strap for holding the bar in place. The strap, however, holds the bar in place on only one side. This produces an asymmetrical distribution of stresses on impact that can damage or break the restraint. Moreover, virtually all of the G-forces are transmitted undiminished from the lap bar to a pair of spaced connecting arms joined to the lap bar in such a way that there is no opportunity for a portion of the energy to be absorbed by the lap bar. Furthermore, the lap bar is formed from a metal tube that extends across the lower part of the abdomen of each passenger causing impact forces to be concentrated in a small area where they can produce severe discomfort or injury.
In view of these and other deficiencies of the prior art, it is an objective to provide a passenger restraint system with a provision that enables a lap bar to be deflected relative to its support arms thereby absorbing a portion of the impact energy. Another object is to provide a passenger restraint system in which a flexible strap or belt is arranged with respect to a U-shaped restraining bar so that the impact forces are symmetrically distributed and in which the belt is arranged to deflect or deform a portion of the restraint to absorb energy.
A further deficiency of many prior restraints is that a lap bar is constructed to enable the upper portion of the body and head to swing forwardly about the waist as a pivot point, thus allowing the head to strike against a seat back. It is therefore an object of the invention to provide a lap bar which will prevent the body from pivoting forwardly about the waist and will at the same time keep the passengers compartmentalized, i.e. confined to predetermined spaces or compartments while the restraint is in use.
Seat belts when used alone can become folded if they are not drawn tight over the hip, forming a sharp edge that acts somewhat as a knife-like edge and which has in the past caused injury because it tended to slice into the body. Another objective of the invention is to prevent this effect.
These and other more detailed and specific objects of the present invention will be apparent in view of the following description which sets forth by way of example but a few of the various ways in which the present invention can be accomplished within the scope of the appended claims.